The invention relates to an inflatable airbag, and more particularly, to an airbag for a vehicle, wherein a joining seam of two fabric ends of the airbag is provided in the vicinity of an opening in the bag fabric such that the fabric ends are overlapped and together form the complete edge region with the opening.
German Offenlegungsschrift 25 52 815, describes an inflatable airbag for the passenger compartment of a motor vehicle. There, the bag fabric is fastened together by joining the edges to form an airbag. The airbag has an opening for connection to a gas generator which is surrounded by an additional strengthening fabric joined to the airbag. Furthermore, the joining seams on the inside of the airbag are also bridged with vulcanized-on or stuck-on fabric strips. Such an arrangement is not particularly favorable from a manufacturing point of view.
An object of the present invention is to protect an opening formed in an airbag against load damage in a manner which is particularly favorable for manufacturing.
The foregoing object has been achieved according to the present invention by providing the joining seam in the vicinity of the opening. The fabric ends are overlapped to form together the complete edge region with the opening.
The openings and their surroundings in an airbag are heavily loaded by the gas pressure forces during inflation and by the hot filling gases, and must therefore be additionally reinforced with respect to the bag fabric.
The need for an added reinforcing fabric piece in the airbag can be avoided by overlapping two fabric ends so that together the ends form the complete edge region and the opening of the airbag.
In this arrangement, the initial cut of the bag fabric can already contain two openings which are congruent after the overlapping of the fabric ends, or else the opening is made in the overlapped region after the joining together of the two fabric ends.
If the two overlapping fabric ends are joined once more by an additional fastening seam which is arranged in the same direction as the joining seam on the opposite side of the opening, or if the two fabric ends are joined to one another in a plane fashion, the edge region which is heavily loaded by pressure forces or temperatures is given a high degree of protection against tearing open of the opening edges. At the same time, this also supports the actual joining seam of the fabric ends.